Figure 3.15. Flower of Psittacanthus sp. (Loranthaceae), a parasitic shrub pollinated by humming-
birds. Photograph byStephan Ingram.spicuous yellow-green flowers, but the species of
Psittacanthus (Loranthaceae) display red flowers
pollinated by hummingbirds (Fig. 3.15). All species
are branch parasites of trees or shrubs. Gaiadendron
punctatum also grows as a small tree, presumably
parasitizing tree roots (see Sargent, "An Exceptional
Mistletoe," p. 82). Although these parasites remove wa-
ter and nutrients from their hosts with penetrating,
suckerlike adventitious roots called haustoria, their
green- or orange-tinted leaves contain chlorophyll and
photosynthesize. Field experiments in Monteverde
showed how germination and seedling establishment
occur in Phoradendron robustissimum on its host
Sapium glandulosum (formerly S. oligoneurum-, Sargent
1995; see Sargent, "Mistletoes," pp. 81-82).
The Balanophoraceae are parasites with under-
ground stems that attach to tree roots with tubers
(modified roots). They lack chlorophyll, have no vis-
ible leaves, and appear to be nonspecific in host
choice. Their existence becomes conspicuous only
when the inflorescences emerge above the soil. The
unisexual flowers are among the world's smallest.
Although nothing is known of their reproductive bi-
ology in Monteverde, some species are fly-pollinated;
others have ant-dispersed seeds with elaiosomes
(oily bodies affixed to propagules; Cronquist 1981).
The distinctly phallic or fungus-like inflorescence of
Helosis cayennensis is a 10-15-cm stalk with an api-
cal red club covered with small geometric scales.
These rare plants grow in forest understory at 900-
1300 m on the Pacific slope and in the San Gerardo
valley (1100 m). The other species of Balanophora-
ceae in Monteverde, Langsdorffia hypogaea, has a
pine cone-like inflorescence that is 4-6 cm across and
barely protrudes above the soil surface. It is covered
with large scales that open to expose a dense column
of many tiny, grayish brown flowers. The inflores-
cences appear in small clusters pushing out of the soil
along forested trails from Bajo del Tigre to the cloud
forest (Sendero Pantanoso). The colonies may persist
in the same locations for several years.
The Ericaceae includes the rare herb Monotropa
uniflora, Indian Pipe (sometimes segregated into the
family Monotropaceae), which produces an unbranched
10—15-cm stalk supporting one or a few large, pinkish
white flowers. This mycotrophic (fungus-associated)
perennial has reduced scale-like leaves and lacks chloro-
phyll. The plants depend on an attachment to a fungus
for food, water, and minerals. Because the fungus makes
a mycorrhizal connection to tree roots, the association
is presumed to be indirectly parasitic (Cronquist 1981).
This species grows in small colonies under oak trees
(Quercus corrugata) in the cloud forest (1500-1600 m).Saprophytes. Saprophytes are plants that derive their
nutrients from dead organic matter, such as decaying58 Plants and Vegetation